Wall plate with one opening for one of more wiring devices

ABSTRACT

There is disclosed a wall plate with a single opening for receiving one or a gang of wiring devices within the single opening. The wall plate has along its vertical axis, a surface of positive first differential and zero second differential, comprised of a combination of splines drawn between points of varying distance from a datum plane. The surface has zero second differential when the rate of height increase of individual splines is constant. The wall plate, when composed of non-conducting material, has a conductive coating on its front surface, on its back surface or on both its front and back surfaces. When the wiring device is a switch, the surface of the switch face follows that of the wall plate. When the wiring device is a receptacle, the surface along the receptacle face is flat in one plane to allow for the proper seating of an inserted plug.

This application is a continuation in part of application Ser. No.10/236,406, filed Sep. 6, 2002, which is a continuation in part ofapplication Ser. No. 10/163,488 filed Jun. 6, 2002.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to the field of electricalwiring devices such as, by way of example, electrical switches and/orreceptacles and accessories for said switches and/or receptacles of thetype installed in building walls.

2. Description of the Related Art

When modifying the wiring in an existing building, whether public,commercial or residential by adding a wiring device such as a switch, areceptacle or a combination of switches and receptacles, it is necessaryto cut a hole in a wall of the building, install a box within the hole,attach the box to a vertical stud and install the wiring device(s) intothe box. In new construction, the box is attached to a stud of an openwall and, thereafter, the wall, which may be sheet rock having anopening for access to the box, is placed over the studs. Theconventional wall box has pairs of mounting ears for mounting the wiringdevices to the box. After the wiring devices are connected to thevarious conductors which they will service, each is fastened withthreaded fasteners such as screws to a pair of ears on the box. Theprocess of connecting a wiring device to various conductors and thenattaching the wiring device with the attached wires to the box is donefor each wiring device located within the box. Then, after all of thewiring devices are finally positioned relative to each other, a wallplate having suitable openings, typically a separate opening in the wallplate for each wiring device, is installed over the wiring devices andthe box.

Typical installations can include one or multiple wiring devicespositioned side by side in a common box. In installations where thereare multiple wiring devices in a common box, the installation of thewall plate can be time consuming. The wiring devices must be alignedwith each other, must be positioned parallel to each other and must bespaced from each other by a distance dictated by the spacing between theopenings or windows in the wall plate. Misalignment and positioningproblems are often caused by wall boxes that are skewed relative to thewall or by walls which may not be flat. It is only after all of thewiring devices are accurately positioned relative to each other that awall plate can be installed around the wiring devices.

A common type of electrical wiring device in use today is the rockertype Decora-branded electrical switch whose activating member pivotsabout a centrally located horizontal axis and is flat in its horizontalplane. The trademark “Decora” is owned by the assignee of the presentinvention. To operate, the rocker switch actuating member is pushed inat the top to supply electricity to a load such as a light, and ispushed in at the bottom to disconnect the source of electricity from theload. Thus, with two or more rocker type switches positioned side byside in a box, the actuating members or paddles of the switches can bein opposite positions at any one time. For example, with two or morerocker type switches positioned side-by-side in a box, the top edges ofthe paddles of the switches will not be in alignment when they are notall in their “on” or “off” position. The in-out positioning of adjacentswitches can also occur when all the switches are in their on or offstate if one of the switches is a 3-way or 4-way switch. The irregularin-out positioning of adjacent switches, particularly with 3-way and4-way switches, can cause operational uncertainty in the mind of theuser as to which switch is on and which switch is off when subsequentactivation or deactivation of less than all of the rocker switches isdesired by a user. Another type of wiring device in use today is areceptacle having a flat face. In normal use, it is not uncommon to ganga receptacle with a switch. A receptacle with a flat face, when gangedwith a switch which is also flat in one plane, typically presents adiscontinuous array of wiring devices which homeowners seem to findobjectionable.

SUMMARY OF THE INVENTION

The present invention relates to a wall plate with a single opening forreceiving one or a gang of two or more wiring devices. The wall platehas one opening with no dividing or separating members for receiving theone or a gang wiring devices and, along its vertical axis, has a surfaceof positive first differential and zero second differential, comprisedof a combination of reference “splines” which extend between points ofvarying distance from a datum plane. The surface has zero seconddifferential when the rate of height increase of individual splines isconstant. The wall plate, when composed of non-conducting material, canhave a conductive coating on its front surface, on its back surface oron both its front and back surfaces. When the wiring device is a switch,the surface of the switch face follows the contour of the wall plate.When the wiring device is a receptacle, the surface of the receptacleface is flat in one plane to allow for the proper seating of an insertedplug.

The foregoing has outlined, rather broadly, a preferred blendingfeature, for example, of the present invention so that those skilled inthe art may better understand the detailed description of the inventionthat follows. Additional features of the invention will be describedhereinafter that form the subject of the claims of the invention. Thoseskilled in the art should appreciate that they can readily use thedisclosed conception and specific embodiment as a basis for designing ormodifying other structures for carrying out the same purposes of thepresent invention and that such other structures do not depart from thespirit and scope of the invention in its broadest form.

BRIEF DESCRIPTION OF THE DRAWINGS

Other aspects, features, and advantages of the present invention willbecome more fully apparent from the following detailed description, theappended claim, and the accompanying drawings in which similar elementsare given similar reference numerals.

FIG. 1 is a front perspective view of a prior art switch and wall plate;

FIG. 2 is a perspective exploded view of a prior art switch, attachmentplate and wall plate, and a box for receiving said prior art device;

FIG. 3 is a front perspective view of a switch and wall plate inaccordance with the principles of the invention;

FIG. 4 is a front perspective view of the switch shown in FIG. 3 showingthe ground/mounting strap and multi-function clips;

FIG. 5 is an exploded view of attachment plate, switch and wall plateaccording to the principles of the invention;

FIG. 6 is a front view of a receptacle and wall plate according to theprinciples of the invention;

FIG. 7 is a front perspective view of a receptacle shown in FIG. 6showing the ground/mounting strap and multi-function clips;

FIG. 8 is an exploded view of the attachment plate, receptacle and wallplate according to the principles of the invention;

FIG. 9 is a front perspective view of alignment plate for a singlewiring device;

FIG. 10 is a perspective view of ground/mounting strap for a wiringdevice;

FIGS. 11 and 11A are bottom perspective views showing ground/mountingstrap attached to a switch (FIG. 11) and a receptacle (FIG. 11A);

FIG. 12 is a plan view of multi-function clip normally attached to thebottom end of the ground/mounting strap;

FIG. 12A is a side view of the multi-function clip of FIG. 12;

FIG. 13 is a plan view of multi-function clip normally attached to thetop end of the ground/mounting strap;

FIG. 13A is a sectional view of the multi-function clip along line A-Aof FIG. 13;

FIG. 14 is an exploded view of a switch in accordance with theprinciples of the invention;

FIG. 15 is a perspective view of the base assembly of the switch of FIG.14;

FIG. 16 is an exploded view of the base assembly of FIG. 15;

FIG. 17 is another exploded view of the switch;

FIG. 18 is still another exploded view of the switch;

FIG. 19 is a partial sectional exploded view of the cam driver of theswitch;

FIG. 20 is a perspective exploded view of the switch showing the lightassembly board;

FIG. 21A is a plan view of the light assembly board;

FIG. 21B is a bottom perspective view of the light assembly board;

FIG. 22 is a perspective exploded view showing the light pipe in thepaddle of the switch;

FIG. 23 is a perspective view of the light pipe;

FIG. 24 is a sectional view along the line 24-24 of FIG. 3;

FIGS. 25A-25C are sectional views along the line 25A-25A, 25B-25B,25C-25C of the paddle of FIG. 14;

FIG. 26 is a perspective exploded view of the switch with another camdriver;

FIG. 27 is a sectional view along the line 24-24 of FIG. 3 where the camdriver is that of FIG. 26;

FIG. 28 is a perspective exploded view of the switch with still anothercam driver;

FIG. 29 is a sectional view along the line 24-24 of FIG. 3 where the camdriver is that of FIG. 28;

FIG. 30 is a front perspective view of a wall plate for a single wiringdevice;

FIG. 31A-31C are sectional views along the lines 31A-31A to 31C-31C ofthe wall plate of FIG. 30;

FIG. 32 is a sectional view of the bottom edge of the wall plate alongthe line 32A-32A of FIG. 30;

FIG. 33 is a sectional view of the top edge of the wall plate along theline 33A-33A of FIG. 30;

FIGS. 34, 34A are views of the top edge of the wall plate of FIG. 30showing the channel and identifying structure;

FIG. 35 is a fragmentary, enlarged perspective of the latching pawl ofthe multi-function clip engaging the tooth rack of the wall plate;

FIG. 36 is a fragmentary, enlarged sectional side view of the wall plateand tab of the alignment plate to indicate how the two components can beseparated following latching;

FIG. 37 is an exploded perspective view of a box, alignment plate andwall plate for two wiring devices;

FIG. 38 is an exploded view of alignment plate and wall plate for threewiring devices;

FIG. 39 is an exploded view of alignment plate and wall plate for fourwiring devices;

FIG. 40 is an exploded view of alignment plate and wall plate for fivewiring devices; and

FIG. 41 is an exploded view of alignment plate and wall plate for sixwiring devices.

DESCRIPTION OF A PREFERRED EMBODIMENT

Referring to FIG. 1, there is illustrated a front perspective view of a“Decora” type electrical wall-type switch 18 and wall plate 16, as partof an assembly 10 of the prior art. Referring to FIG. 2, there is showna perspective exploded view of the prior art device of FIG. 1 of wallbox 13, electrical wiring device such as switch 18, attachment plate 30and wall plate 16. A suitable aperture is cut into a wall to provideaccess for the box 13 for mounting to a stud 15, or to permitinstallation of a suitable box to an adjacent stud or directly to thematerial of the wall (such as plasterboard). The box 13 is chosen to belarge enough to accept as many wiring devices as are to be mountedtherein. The box 13 is made of metal or plastic, depending upon localCode requirements, and has one or more openings in its sides or back topermit the introduction of electrical wiring or cables into the interiorof the box 13. Box 13 has mounting means 19 to permit the box to beanchored to the adjacent stud 15. The box supports a pair of mountingears 21 for each wiring device that is to be mounted within the box.Each mounting ear contains a threaded aperture 23 to which is fastened amounting screw of the wiring device such as, for example, rocker switch18 or a receptacle. In the normal order of assembly, electrical cablesare passed through knock out openings 17, for example, to the interiorof the box. The ends of the electrical cables are stripped of insulationand attached to terminals (contacts) on the side or rear of the body 20of the switch 18 or a receptacle. After the electrical cables areattached to terminals on the side or rear of the body of the switch, theswitch is pushed into the box and held in position by screws (not shown)that are passed through clearance openings such as elongated mountingslots 25 and threaded into openings 23 of ears 21 to mount switch 18within and to the box 13. Thereafter, attachment plate 30 is positionedaround the front of the switch and secured to the switch with mountingscrews 26 which pass through clearance openings 32 in the attachmentplate and are threaded into openings 24 formed in the mounting/groundstrap of the wiring device. Attachment plate 30 also contains a mainaperture 34 of a shape complimentary with the profile of the front ofthe switch 18 which extends through it. Aperture 34 in FIG. 1 isrectangular to accept the front of the switch 18 or a receptacle. Thehead of the screw which passes through aperture 25 of switch 18 andengages threaded opening 23 of mounting ears 21 is larger than theaperture 25 and, therefore, holds switch 18 or a receptacle captive tothe box 13 and to the wall surface (not shown). In a similar manner, thehead of the screw which passes through aperture 32 of the attachmentplate 30 and engages threaded opening 24 of the ground strap of theswitch is larger than the aperture 32 and, therefore, holds attachmentplate 30 captive to the switch 18.

At each of the ends 36, 38 respectively, of attachment plate 30 are twolatching pawls 40, 42 which are formed as extensions of attachment plate30 but are thinner in cross-section. One end 36 also terminates in anangled leg 48 which extends at about a 45 degree angle with respect tothe horizontal edge of end 38 of wall plate 30 and is used to helprelease an attached wall plate.

Wall plate 16 is proportioned to fit over attachment plate 30 and box 13into which the single wiring device, such as rocker switch 18, or areceptacle is placed and to which it is fastened.

To attach wall plate 16 to attachment plate 30, pawls 40, 42 ofattachment plate 30 are made to engage saw-tooth shaped racks 81 on theinner surfaces of end walls 70 and 72 of wall plate 16 as the wall plateis pushed in.

FIG. 3 is a front perspective view of a wiring device such as switch 110and wall plate 138 in accordance with the principles of the presentinvention; FIG. 4 is a front perspective view of the switch 110 of FIG.3 showing ground/mounting strap and multi-function clips; and FIG. 5 isan exploded view of FIG. 3 showing attachment plate, switch and wallplate. Referring to FIGS. 4 and 5, the switch 110 has an actuatingpaddle 111 which pivots about an axis at its upper end and is biased byan internally located spring member to assume the same at-rest positionwhen in its “on” and “off” position. Repeated pressing and releasing onthe face of the paddle 111 of the switch alternately closes and opens aset of contacts within the switch body to alternately connect anddisconnect a load such as a light with a source of electricity each timethe paddle is pressed and released. Thus, regardless of whether gangedswitches are on-off switches, 3-way switches or 4-way switches, the topand bottom edges of each switch will always be aligned with the top andbottom edges of all the other switches of the gang. An on-off indicatorsuch as a light 112 is provided in the paddle to indicate to a user whenthe switch is in its on position or off position. For example, when thelight 112 is on, the switch will be in its off position, and when thelight is off, the switch will be in its on position. The paddle 111 ofthe switch is not located within a frame and functionally complementsthe wall plate 138. The paddle of the switch has a length-width ratiodimension and surface configuration which provides a contact surface ofincreased size which is more easy to identify and use.

The switch 110 is attached to a ground/mounting strap 123 having ends122 which provide increased surface area for contact with the surface ofa wall and provides support for multi-function clips 130, 151 attachedto the ends 122 by fastener means such as screws, rivets, spot welds,pressure bonding, TOX process or the like.

Referring to FIG. 10, there is shown a perspective view of theground/mounting strap 123 for a wiring device such as switch 110. Strap123 has a base support member 150 located between two intermediatesupport members 152 bent at right angles to the base member 150 andwhich terminate with an outward projecting end 122. The two intermediatesupport members 152 and the base support member cradles and are securelyattached to the wiring device, such as switch 110, with rivets, screwsor the like 155 (see FIG. 11 which is a bottom perspective view showingground/mounting strap attached to a switch) which pass through openings154 in the base support member. A ground terminal 163 which projects outfrom the ground/mounting strap and having a threaded opening forreceiving a screw 125 is provided for connection to a ground wire. Eachend 122 of the strap 123 is rectangular in shape and has two openings126 and 128. Opening 126 can be circular, oval, square or rectangularand is a clearance opening for mounting screws 108 which can be providedby the manufacturer of the wiring device for attaching the wiring deviceto a box. The distance between centers of openings 126 in ends 122 ofthe ground/mounting strap is equal to the distance between the centersof openings 23 in ears 21 of box 13 (see FIG. 2) to allow mountingscrews 108 to engage and be held captive by threaded openings 23.Opening 128 in each end 122 of the strap is a clearance opening for analignment pin which is a part of and is located on an alignment plate.Additional openings can be provided in the ends 122 for attaching and/oraligning a clip to the end of the ground/mounting strap. The ends 122are flat rectangular members which provide an increased area forincreased contact with a wall surface. See FIG. 2 which shows therelatively small ends of a prior art ground/mounting strap where, if thescored washers 31 are removed from the strap, the only surface left forcontact with a wall surface is the material around the opening of themounting ear 21.

The end 122 of ground/mounting strap 122 has a width “X” of about 1.563inches and a depth “Y” of about 0.318 inches. These dimensions are notcritical. However, the distance between the edges 129 of the ends 122 ofthe strap should not be greater than 4.6 inches to allow a wall plate tofit over and cover the ground/mounting strap. The ground/mounting strap123 can be of sheet metal and is secured to the switch with screws,rivets or any convenient fastening means 155. Screw terminals 126located on either side of the body of the switch are provided to receivephase and neutral wire conductors, not shown.

Multi-function clips 130, 151 are attached to the ends 122 of theground/mounting strap. The multi-function clips can be composed ofphosphor bronze, spring brass, spring steel or the like. Referring toFIG. 12, there is shown a plan view of multi-function clip 130 normallyattached to the bottom end of the ground/mounting strap, and FIG. 12A isa side view of the multi-function clip 130 of FIG. 12. Clip 130 is theclip that is attached to the bottom end 122 of ground/mounting strap 123and has openings 132 and 134. When clip 130 is attached to the end ofground/mounting strap, opening 132 is aligned with opening 126 of theground/mounting strap, and opening 134 is aligned with opening 128 inthe strap end 122. Opening 132 is a clearance opening for a threadedfastener such as screw 108 used to couple the wiring device to a box.Opening 132 can be round, square, oval or rectangular to allow thethreaded fastener to be moved up, down and sideways so the fastener canbe aligned with the threaded opening in the box when connecting thewiring device to the box.

Opening 134 in clip 130 is substantially circular and has three inwardlyprojecting members 133 bent upward at an angle of between 10 degrees and30 degrees toward the face of the wiring device. An angle of 20 degreeswas found to be preferred. The ends of the three projecting members 133form an opening slightly smaller than the outer diameter of an alignmentpin 118 on an alignment plate (see FIG. 9) and flex or bend upward asthe alignment pin enters the opening 134 from the rear. The ends of theprojecting members 133 frictionally engage and hold captive thealignment pin to inhibit its easy removal from the multi function clip.Located at the end 147 of clip 130 are latching pawls 140 each slightlymore than one-half of an inch in length. The end 149 of each latchingpawl 140 is bent upward at an angle of between 20 degrees and 60 degreesand is used to engage tooth shaped racks on the inside surface of theends of a wall plate to hold the wall plate captive (see FIG. 35). Theends 149 of the latching pawls 140 capture and securely hold the wallplate when the upward bend of the latching pawl 140 is between 20degrees and 60 degrees, where a bend of about 40 degrees was found to bepreferable. The multi-function clip 130 is just that, a clip whichperforms a plurality of functions not disclosed in the prior art.

The opening 143 in the multi-function clips can be provided forattaching the clip to the end of the ground/mounting strap with, forexample, rivets, screws, the TOX process etc. Openings 145 can beprovided for alignment purposes when attaching the clip to the end ofthe strap. The distance between the side edges 154 of the clip shouldnot exceed 1.533 inches to allow the clip to be attached to the end ofthe mounting/ground strap without extending over the side edges of thestrap 123. The clip shown in FIGS. 12 and 12A is the clip that isattached to the bottom end of the ground/mounting strap.

Referring to FIG. 13, there is shown a plan view of the multi-functionclip normally attached to the top end of the ground/mounting strap andFIG. 13A is a sectional side view of the multi-function clip along lineAA of FIG. 13. The clip shown in FIGS. 13 and 13A is similar to the clipshown in FIGS. 12 and 12A except that end 157 of clip 151 is bent upwardand opening 153 for the threaded fastener has a tab 155 which extendsinto opening 153, and is bent at a slight downward angle toward the backof the switch. Tab 155 is provided to engage and hold captive thethreaded body of fastener 108 and, in addition, helps to provide aground connection between the strap and the threaded fastener to insurethat the switch is connected to ground. As with clip 130, openings 153in clip 151 and opening 126 in the strap are aligned with each otherduring assembly to permit the fastening means to be aligned with thethreaded opening in the box as the switch is being attached to the box.The distance between the edges 147 of the clips should not exceed 1.533inches to allow the clip to be attached to the end of theground/mounting strap without extending over the side edges of the ends122 of the strap 123.

Referring to FIG. 6, there is shown a front view of a receptacle andwall plate according to the principles of the invention; FIG. 7 is afront perspective view of the receptacle 520 of FIG. 7 showingground/mounting strap and multi-function clips; and FIG. 8 is anexploded view of FIG. 6 showing attachment plate, receptacle plate,receptacle and wall plate. Referring to FIGS. 7 and 8, the receptacle520 is intended for 15 Amp. 125 VAC to 20 Amp. 125 VAC (not illustrated)where, according to NEMA specification 5-15R, each individual receptaclehas two slot openings 524 and 526 for receiving the flat blades of asuitable plug and a semi-circular ground blade opening 528. Opening 526is larger than the opening 524 to allow a two blade plug to be insertedin only one way to maintain correct electrical polarization. The contactin the larger slot is connected to the neutral conductor and, bymaintaining the correct polarization, the external metal parts ofappliances such as toasters, TV's etc. can be grounded through theneutral conductor. The semi-circular ground blade prevents a plug frommaking a reverse polarity connection with the receptacle.

Receptacle 520 is attached to a ground/mounting strap 123 having ends122 which provide increased surface area for contact with the surface ofa wall and provides support for multi-function clips 130, 151 attachedto the ends 122 by fastening mean such as screws, rivets, spot welds,pressure bonding, TOX process or the like.

Referring to FIG. 10, there is shown a perspective view of theground/mounting strap 123 for a wiring device such as receptacle 520.Strap 123 has a base support member 150 located between two intermediatesupport members 152 bent at right angles to the base member 150 andwhich terminates with an outward projecting end 122. The twointermediate support members 152 and the base support member cradles andare securely attached to the receptacle 520 with rivets, screws or thelike (see FIG. 11A which is a bottom perspective view showingground/mounting strap attached to a receptacle) which pass throughopenings 154 in the base support member. A ground terminal 163 whichprojects out from the ground/mounting strap and having a threadedopening for receiving a screw 125 is provided for connection to a groundwire. Each end 122 of the strap 123 is rectangular in shape and has twoopenings 126 and 128. Opening 126 can be circular, oval, square orrectangular and is a clearance opening for mounting screws 108 which canbe provided by the manufacturer of the wiring device for attaching thewiring device to a box. The distance between centers of openings 126 inends 122 of the ground/mounting strap is equal to the distance betweenthe centers of openings 23 in ears 21 of box 13 (see FIG. 2) to allowmounting screws 108 to engage and be held captive by threaded openings23. Openings 128 in each end 122 of the strap is a clearance opening foran alignment pin which is a part of and is located on an alignmentplate. Additional openings can be provided in the ends 122 for attachingand/or aligning a clip to the end of the ground/mounting strap. The ends122 are flat rectangular members which provide an increased area forincreased contact with a wall surface. See FIG. 2 which shows therelatively small ends of a prior art ground/mounting strap where, if thescored washers 31 are removed from the strap, the only surface left forcontact with a wall surface is the material around the opening of themounting ear 21. The end 122 of ground/mounting strap 122 has a width“X” of about 1.563 inches and a depth “Y” of about 0.318 inches. Thesedimensions are not critical. However, the distance between the edges 129of the ends 122 of the strap should not be greater than 4.6 inches toallow a wall plate to fit over and cover the ground/mounting strap. Theground/mounting strap 123 can be of sheet metal and is secured to thereceptacle with screws, rivets or any convenient fastening means 155.Screw terminals 126 located on either side of the body of the receptacleare provided to receive phase and neutral wire conductors, not shown.

Multi-function clips 130, 151 are attached to the ends 122 of theground/mounting strap. The multi-function clips can be composed ofphosphor bronze, spring brass, spring steel or the like. Referring toFIG. 12, there is shown a plan view of multi-function clip 130 normallyattached to the bottom end of the ground/mounting strap, and FIG. 12A isa side view of the multi-function clip 130 of FIG. 12. Clip 130 is theclip that is attached to the bottom end 122 of ground/mounting strap 123and has openings 132 and 134. When clip 130 is attached to the end ofthe ground/mounting strap, opening 132 is aligned with opening 126 ofthe ground/mounting strap, and opening 134 is aligned with opening 128in the strap end 122. Opening 132 is a clearance opening for a threadedfastener such as screw 108 used to couple the wiring device to a box.Opening 132 can be round, square, oval or rectangular to allow thethreaded fastener to be moved up, down and sideways so the fastener canbe aligned with the threaded opening in the box when connecting thewiring device to the box.

Opening 134 in clip 130 is substantially circular and has three inwardlyprojecting members 133 bent upward at an angle of between 10 degrees and30 degrees toward the face of the wiring device. An angle of 20 degreeswas found to be preferred. The ends of the three projecting members 133form an opening slightly smaller than the outer diameter of an alignmentpin 118 on an alignment plate (see FIG. 9) and flex or bend upward asthe alignment pin enters the opening 134 from the rear. The ends of theprojecting members 133 frictionally engage and hold captive thealignment pin to inhibit its easy removal from the multi function clip.Located at the end 147 of clip 130 are latching pawls 140 each slightlymore than one-half of an inch in length. The end 149 of each latchingpawl 140 is bent upward at an angle of between 20 degrees and 60 degreesand is used to engage tooth shaped racks on the inside surface of theends of a wall plate to hold the wall plate captive (see FIG. 35). Theends 149 of the latching pawls 140 capture and securely hold the wallplate when the upward bend of the latching pawl 140 is between 20degrees and 60 degrees, where a bend of about 40 degrees was found to bepreferable. Multi-function clip 130 is just that, a clip which performsa plurality of functions not disclosed in the prior art.

The opening 143 in the multi-function clips can be provided forattaching the clip to the end of the ground/mounting strap with, forexample, rivets, screws, the TOX process etc. Openings 145 can beprovided for alignment purposes when attaching the clip to the end ofthe strap. The distance between the side edges 154 of the clip shouldnot exceed 1.533 inches to allow the clip to be attached to the end ofthe mounting/ground strap without extending over the side edges of thestrap 123. The clip shown in FIGS. 12 and 12A is the clip that isattached to the bottom end of the ground/mounting strap.

Referring to FIG. 13, there is shown a plan view of multi-function clipnormally attached to the top end of the ground/mounting strap and FIG.13A is a sectional side view of the multi-function clip along line A-Aof FIG. 13. The clip of FIGS. 13, 13A is attached to the top of theground/mounting strap. The clip shown in FIGS. 13 and 13A is similar tothe clip shown in FIGS. 12 and 12A except that end 157 of the clip 151is bent upward and opening 153 for the threaded fastener has a tab 155which extends into opening 153 and is bent at a slight downward angletoward the back of the receptacle. Tab 155 is provided to engage andhold captive the threaded body of fastener 108 and, in addition, helpsto provide a ground connection between the strap and the threadedfastener to insure that the receptacle is connected to ground. As withclip 130, openings 153 in clip 151 and opening 126 in the strap arealigned with each other during assembly to permit the fastening means tobe aligned with the threaded opening in the box as the receptacle isbeing attached to the box. The distance between the edges 147 of theclips should not exceed 1.522 inches to allow the clip to be attached tothe end of the ground/mounting strap without extending over the sideedges of the ends 122 of the strap 123.

Referring to FIG. 9, there is shown a front perspective view ofalignment plate 114 of FIG. 5 for a single wiring device such as aswitch or a receptacle. Alignment plate 114, which can be composed ofany suitable material such as brass, aluminum, cold rolled steel,plastic, a plastic coated with a conducting material, etc., has acentrally located opening 116 sized to accept the body of a wiringdevice. Centrally located at opposite top and bottom ends of opening 116and either opening into or separated from opening 116 are two clearanceopenings 117 for mounting screws 108 used to secure the wiring device, aswitch or a receptacle, and alignment plate 114 to box 13. Locatedbetween the outer edge of each clearance opening 117 and the end 121 ofplate 114 is an alignment pin 118. Clearance openings 117 in alignmentplate 114 which can have an open end as shown in FIG. 9 or be an openingfully encircled by material. When the alignment plate is attached to theground/mounting strap, openings 128 in the ends 122 of theground/mounting strap are clearance openings for alignment pins 118 andare aligned with openings 134 in the multi-function clips 130,151. Thus,the alignment pins are positioned to enter openings 134 inmulti-function clips 130, 151 attached to the lower and upper ends ofthe ground/mounting strap 123 of the wiring device as the wiring deviceis being attached to the alignment plate. Alignment plate 114 can havetwo ribs 119 and has a downwardly extending tab 120 which extends fromthe bottom edge and is used to facilitate removal of a wall plate fromaround the face of the wiring device. The alignment plate 114, whenattached to the wiring device, covers the box in which the wiring deviceis installed. The alignment plate 114 shown in FIG. 9 is for a singlewiring device.

The alignment plate 114 helps to overcome difficulties encountered withrespect to mounting and positioning wiring devices such as one or moreswitches, a switch and/or a receptacle, or one or more receptacles to abox prior to placing a wall plate around the wiring devices. Prior tomounting a wall plate, various difficulties can be encountered such asaligning the wiring devices with each other, positioning the wiringdevices to be parallel to each other, adjusting the spacing between thewiring devices to be equal and uniform and fixing all of the wiringdevices to be flat against the wall. These difficulties are overcomewith alignment plate 114 which has a single opening and a pair ofalignment pins in combination with multi-function clips. The opening inthe alignment plate is sized to receive one or more wiring devices whichare to be positioned side by side in a box and the alignment plate has apair of alignment pins 118 which hold and accurately position each ofthe wiring device relative to each other and along a flat plane. Eachset of alignment pins on the alignment plate is located on a verticalaxis which defines the center for a wiring device and each wiring devicehas a multi-function clip at each end of the ground/mounting strap forfrictionally receiving and holding captive the alignment pins on thealignment plate. When being assembled, the wiring devices are firstattached to the alignment plate and the alignment plate, which now holdscaptive the wiring devices, is attached to a wall box by means ofmounting screws. Thereafter, a wall plate is positioned around thewiring devices without requiring any further adjustments by simplypressing the wall plate in toward the wall to allow the ends 149 of thelatching pawls 140 of the multi-function clips to engage teeth on theinside ends of the wall plate.

The multi function clips, in addition to clamping the wall plate to theground/mounting strap, helps to overcome various difficultiesencountered with respect to mounting and positioning one or moreelectrical wiring devices to a box to allow a wall plate to be quicklyand easily positioned around the wiring devices and to also be flatagainst the wall. Each wiring device according to the present inventionhas at each end of the ground/mounting strap a multi-function clip thathas locating openings 134 for receiving and engaging alignment pins 118on the alignment plate 114. The pins on the alignment plate, whenengaged by the close clearance locating openings 134 in themulti-function clips, accurately positions each wiring device in alldirections, sideways, up, down, and the plate itself positions thewiring device along a flat plane to allow a wall plate to be positionedaround a single wiring device or a gang of wiring devices without anyinitial or subsequent adjustment being required. Each pair of alignmentpins on the alignment plate is located on a substantially vertical axiswhich accurately defines the center of a wiring device, although it iswithin the scope of the present invention to provide other alignments,as well. The opening 134 in each multi-function clip receives and holdscaptive an alignment pin 118. The multi-function clips, in cooperationwith the alignment pins, accurately positions and aligns all wiringdevices mounted on the alignment plate. As is disclosed below, thealignment plate can be made to receive one or more wiring devices. Afterthe wiring device(s) are attached to the alignment plate, the wiringdevice(s), together with an alignment plate are attached to a wall boxby means of threaded fasteners such as screws which pass throughopenings 132 of the multi-function clips, openings 127 in theground/mounting strap and openings 117 of the alignment plate. Thealignment plate provides a substantially flat rigid support for thewiring devices and insures that all the wiring devices are accuratelypositioned to allow a wall plate to be placed around the wiring deviceswithout requiring any further adjustment.

During assembly, the electrical cables in the box are stripped ofinsulation and are attached to terminals on the side or back of a wiringdevice such as a switch or receptacle. After the wires are attached tothe wiring device, the alignment plate is positioned behind the wiringdevice by threading the wiring device through the opening in thealignment plate. The front face of the alignment plate is now movedtoward the back face of the ends of the ground/mounting strap. As thealignment plate moves toward the wiring device, the alignment pins 118on the alignment plate enter openings 128 in the strap and openings 134in clips 130. As the alignment pins enter the openings 134, they forcethe upwardly bent projections 133 to resiliently move upward and spreadslightly apart to allow the alignment pins to fully enter openings 134.The ends of the upwardly bent projections engage and hold captivealignment pins 118 and strongly resist backward movement and withdrawalof the pins from the openings 134. The switch or receptacle which is nowattached to the alignment plate and is connected to the electricalwires, is inserted into the box. As the wiring device is inserted intothe box, screws 108 located in openings 132 in the multi-function clipsand clearance openings 117 in alignment plate are aligned with andthreaded into openings 23 to hold both the alignment plate and wiringdevice(s) to the box and wall surface. The head of the screw whichpasses through opening 126 of the end of the ground/mounting strap ofthe wiring device and opening 132 in the clip is larger than eitheropening and, therefore, holds the wiring device and alignment plate 114.

The wall plate is now placed over the installed wiring devices. It is tobe noted (see FIGS. 3, 4 and 5) when the wiring device is the switchhere disclosed, the paddle of switch 110 is frameless. It is not locatedwithin a frame. Thus, the switch must be accurately positioned withinthe wall plate to insure that the paddle is free to move withouttouching any surface of the wall plate or a side surface of anadjacently positioned wiring device.

Each multi-function clip 130, 151 contains two side-by-side latchingpawls 140. See FIGS. 12-13A. Each latching pawl 140 is bent downwardtoward the back of the wiring device by about 40 degrees. After thewiring device is attached to the alignment plate, the two latching pawls140 of the multi-function clip at the bottom end of the wiring devicestraddles tab 120 on the alignment plate. Tab 120 (see FIG. 36)functions as a tool pivot point to allow the wall plate 138, whenattached to the alignment plate, to be easily removed from around theswitch or receptacle. A slot 74 in the lower edge of the wall plate 138provides access for the insertion of a small flat tool such as a screwdriver to facilitate removal of the wall plate from the wiring device.

Wall plate 138 is proportioned to fit over alignment plate 114, the ends122 of the ground/mounting strap 123 and the box within which the wiringdevice is located. The wall plate 138 is located around the wiringdevice and locked in position by pushing the wall plate toward thewiring device until the ends of the latching pawls 140 engage teeth onthe inside wall of the top and bottom edges of the wall plate.

Referring to FIGS. 14-24, there is shown in detail multiple views of theswitch and components of the switch of FIGS. 3-5. More specifically,FIG. 14 is an exploded view of a switch in accordance with theprinciples of the invention; FIG. 15 is a perspective view of the baseassembly of the switch of FIG. 14; FIG. 16 is an exploded view of thebase assembly of FIG. 15; FIG. 17 is another exploded view of theswitch; FIG. 18 is still another exploded view of the switch; FIG. 19 isa partial sectional exploded view of the cam driver of the switch; FIG.20 is a perspective exploded view of the switch showing the lightassembly board; FIG. 21A is a plan view of the light assembly board;FIG. 21B is a bottom perspective view of the light assembly board; FIG.22 is a perspective exploded view showing the light pipe in the paddleof the switch; FIG. 23 is a perspective view of the light pipe; and,FIG. 24 is a sectional view along the line 24-24 of FIG. 3.

Referring to FIG. 14, there is shown an exploded view of base assembly300 and frame assembly 400 which, when joined together and coupled topaddle 112 forms a single pole switch, and FIG. 15 which shows aperspective view of the base assembly 300. Base assembly 300 includesshell member 302 composed of electrically insulating material and havinga longitudinal channel 304 which extends along the length of shellmember 302 and is centrally located between the side walls 306, 308 ofmember 302. Channel 304 is sized to receive a slider 320 (see FIG. 16)which slides back and forth in channel 304. Located in shell member 302and beyond each end of channel 304 are clearance openings 310 forreceiving fastening means 124 such as rivets, screws or the like to lockthe ground/mounting strap 123, the base assembly 300 and the frameassembly 400 together. Side wall 308 of the shell member has an opening309 adapted to receive a stationary terminal assembly 312 and side wall306 has an opening 336 for receiving brush terminal assembly 346, eachmore fully shown in FIG. 16.

Referring to FIG. 16, stationary terminal 312 consists of a rectangularplate 313 and a substantially non-yielding contact bearing arm 314 bentat a right angle to the plate and having a contact 316. Stationaryterminal 312 is of conducting material such as brass, etc. An inverted Ushaped slot 318 located in rectangular plate 313 is a clearance openingfor terminal screw 320 which threads into pressure plate 323 locatedbehind plate 313. In operation, as terminal screw 320 is tightened, thebottom surface of the head of screw 320 and pressure plate 323 movetoward each other to clamp the rectangular plate 313. Stationaryterminal assembly 312 is adapted to be connected to an electricalconductor by either placing a turn of electrical conductor such as awire under the head of the screw 320 or by inserting a straight end ofthe conductor between the pressure plate 323 and the rectangular plate313, and then tightening screw 320 to lock the conductor between eitherplates 313 and 323, or the plate 313 and the head of the screw 320.Looking at side wall 308 of shell member 302, each of the two side edges311 of opening 309 contain a vertical slot or rail 315 provided toreceive and hold the side edges of rectangular plate 313. Sliding therectangular plate 313 of the stationary terminal assembly 312 down intothe slots or rails 315 in the edges of the opening 309 positions andholds the stationary terminal assembly 312 in position within theopening 309 of side wall 308 of shell member 302.

Brush terminal assembly 346 includes a rectangular plate 380 composed ofelectrical conducting material such as brass etc., which supports ayieldable contact bearing arm 344 having a contact 317. An inverted Ushaped slot 381 located in rectangular plate 380 is a clearance openingfor terminal screw 386. Terminal screw 386 freely passes thru clearanceopening 381 and threads into pressure plate 388. Tightening terminalscrew 386 clamps the rectangular plate 380 between the bottom surface ofthe head of the screw 386 and the pressure plate 388. Brush terminalassembly 346 is adapted to be connected to an electrical conductor byeither placing a turn of the conductor under the head of the screw orinserting a straight end of the conductor between the pressure plate 388and the rectangular plate 380. Tightening the screw 386 locks theconductor between the screw head and plate 380, or between plate 380 andpressure plate 388. Looking at side wall 306 of shell member 302, thetwo edges 303 of opening 384 each has a narrow vertical slot or rail 317for receiving and holding the side edges of rectangular plate 380.Sliding rectangular plate 380 of brush terminal assembly 346 down intoslots or rails 317 in the edges of opening 384 positions and holds thebrush terminal assembly in opening 384 of the side wall 306 of the shellmember 302.

The stationary terminal assembly 312 and the brush terminal assembly 346are made of conductive material so that a circuit can be completedbetween the conductive wires connected to screw terminals 320, 386.Preferably, the conductive components are all of substantial grade, goodquality electrical materials so that substantial currents, for example10 or 20 amperes, can repeatedly be carried for extended periods of timewithout significant heat generation, electrical losses or excessivearcing. Such materials can include silver alloys for the contacts,beryllium copper alloy for the brush arm and brass for the remainingconductive components.

Referring to FIGS. 15 and 16, slider 320, when positioned within channel304 can freely slide back and forth between the side walls 319, 321 fromone end of the channel to the other end of the channel. Slider 320 has,at one end, a rectangular funnel shaped slot opening 322 which extendscompletely through the slider and is provided to receive cam follower370 of cam 366. It is understood that the rectangular funnel shaped slotopening 322 in not restricted to an end of the slider, but can belocated anywhere along the slider to a place where it is convenient todo so. Projecting downward from the bottom surface of slider 320 andabout mid-way between the ends of the slider is a triangular shaped camfollower 324. Projecting upward from the top surface of the slider 320and about mid-way between the slider ends is a hold down projection 326.Also projecting upward from the top surface of the slider is a brushterminal control projection 327. The space 329 between hold downprojection 326 and brush terminal control projection 327 is provided toreceive spring contact arm 344 of brush terminal assembly 346. Movementof the slider 320 in direction “A” causes projection 327 to urge contactarm 344 to bend downward and move away from stationary contact 316.Movement of the slider 326 in direction “B” causes projection 327 tomove up which allows contact arm 344 to spring back and allow contact317 to make electrical contact with contact 316. A bumper support member328 which projects outward from the side of the slider 320 providessupport for a rubber O ring 330. With the slider located in sliderreceiving channel 304, O ring 330 moves back and forth between stops332, 334 of opening 336 in side wall 321 (see FIG. 15) as the slider isdriven from one end of channel 304 to the other. The O ring is used tocushion the stopping of the slider 320 by contacting stops 332, 334located at the ends of opening 336 in wall 321. Contact 317 of brushterminal assembly 346 (see FIG. 16) is biased by spring arm 344 to moveupward toward stationary contact 316. To help offset some of the upwardforce exerted by arm 344 which moves contact 317 toward contact 316 asthe slider is moved down, a helper spring 338 is provided. Helper spring338 also helps to balance the feel of the rocker paddle as the switch isoperated.

Movable spring contact arm 344 of brush terminal assembly 346 is springbiased to move contact 317 up toward stationary contact 316. Therefore,more force is needed by the slider 320 to move contact 317 on springcontact arm 344 out of engagement with stationary contact 316 than isneeded to close the contacts. Referring to FIG. 16, helper spring 338 isused to help overcome this force. Helper spring 338 is a strip of flatspring metal folded about its center with a generous radius to have twolegs 337, 339 which forms an inverted V. The inverted V shaped helperspring 338 fits in chamber 340 located at the top end of channel 304(see FIG. 16) with the apex of the V being at the top of the channel. Asslider 320 is moved up, the spring bias of spring contact arm 344assists in closing contacts 316, 317. As the slider moves up and thecontacts close, the end 342 of slider 320 contacts leg 339 of helperspring 338 and urges it to move toward leg 337. At this time, helperspring 338 is compressed and now biases slider 320 to move down. Whenthe contacts 316, 317 are being opened, helper spring 338 urges sliderto move down against the force of the spring contact arm 344. Thus,spring 338 helps to overcome the force exerted by the spring contact arm344 of the brush terminal 344 on the slider when the spring contact arm344 is being moved down to open the contacts 316, 317.

Wall 348 at the end of chamber 340 contains a slot opening 350 whichallows the end 342 of slider 320 to enter chamber 340 to engage and moveleg 339 toward leg 337 of helper spring 338. Wall 348 helps to keephelper spring 338 within the chamber 340.

As seen in FIG. 24, located directly beneath slider receiving channel304 and opening into channel 304 is spring chamber 354. Spring chamber354 is elongated, has a rectangular cross-section and contains a flatcam shaped leaf spring 352. The spring chamber 354 can be centrally andsymmetrically disposed in the switch base 300 and has support bars 356at each end for supporting flat cam shaped leaf spring 352. Locatedbeyond each support bar 356 is an end pocket 365. The overall length ofchamber 354 is determined by the length of the flat cam shaped leafspring 352.

Cam shaped leaf spring 352 is formed from a flat resilient steel strip,preferably spring steel, and has a profile substantially similar to thatshown in FIG. 22. The flat cam shaped leaf spring 352 has a profile thatis symmetrical about a center apex 358. Moving along the spring 352 fromthe apex to the ends, the spring has a short down sloping cam portion359 on each side of the apex 358 which, together with support sections357 forms a depression 360, 362 at each side of the apex. The supportsections 357 rest on support bars 356 and terminate in U shaped outerend portions 364 which resides in end pockets 365. The apex 358, thecentrally located rise of the spring and the flat short cam portions 359on each side of the apex and joined by support sections 357 provide asurface discontinuity rather than a smooth transition for the cam 324 asit travels over the apex.

Referring to FIGS. 16 and 24, cam 366 is used to move the slider backand forth between its left and right hand positions which corresponds tothe off and on position of the switch. Cam 366 has two cylindricalshaped projections 368 which are aligned with each other and extend outfrom the sides to form an axel support shaft rotatably received bysupport bearing openings 378 located in side walls 319, 321 of theslider receiving channel 304. In operation, cam 366 can rock back andforth in a clockwise and counterclockwise direction about the axeldefined by the projections 368. Extending downward and below projections368 is cam follower 370 which fits in the rectangular funnel shaped slotopening 322 in slider 320 with minimum clearance. Extending upward fromprojections 368 is cam control surface 430 having a first pocket 374located at the left of the cam, and a second pocket 372 located at theright of the cam. Looking at the profile of the cam 366 as shown in FIG.24, pocket 372 is at the right side of the axes of rotation of the cam,and pocket 374 is at the left side of the axes of rotation of the cam.Thus, when the slider is at its right hand position, application of adownward force on pocket 372 will cause the cam follower 370 to rotatein a clockwise direction to cause slider 320 to move to the left. In asimilar way, application of a downward force on pocket 374, when theslider is at its left hand position, will cause the cam follower 370 torotate in a counterclockwise direction to cause the slider to move tothe right. Thus, pressing down on pocket 372 causes the cam to rotateclockwise which causes the cam follower 370 to move the slider to theleft. Thereafter, pressing down on pocket 374 will now cause the cam torotate counterclockwise to cause the cam follower to move the slider tothe right. Alternately pressing on pockets 372 and 374 will cause theslider to move back and forth, first in one direction and then in theother direction.

Projecting upward from the bottom member 401 of frame assembly 400, andof the same material as the bottom member, are two hook members 396 (seeFIGS. 16 and 18) which engage and pivotly hold cooperating hook members418 (see FIG. 17) which project down from subplate 412 of the rockerassembly 398. Frame assembly 400 includes a rectangular clearanceopening 402 located in bottom member 401 which is aligned with the topof cam 366 and through which an actuator 405 (see FIGS. 18 and 19) ofcam driver 431 projects to engage and operate cam 366.

The cam 366 is operated by cam driver 431(FIG. 19) which consists of acylindrical shaped member 409, a plunger 403, an actuator 405, and aconical shaped coil spring 407. The cam driver 431 engages and drivescam 366, first in a clockwise direction, then in a counter-clockwisedirection each time plunger 403 is moved down. The open endedcylindrical shaped member 409 supports two ears 411, each having athreaded opening for receiving a holding member such as a screw tosecure the member 409 to frame assembly 400. Member 409 contains a firstopening 413 at its lower end and a second opening 415 at its upper end.The first opening 413 at the lower end of the cylindrical shaped member409 is sufficiently large to avoid obstructing or interfering with therectangular clearance opening 402 when the member 409 is mounted tobottom member 401 of the frame assembly 400 and is positioned overopening 402. The cylindrical shaped member 409 supports an internal,inwardly projecting ridge 417 located between the first 413 and second415 openings.

Plunger 403 slidably fits within member 409. The outside diameter ofplunger 403 is slightly smaller than the diameter of the second opening415 in the upper end of cylindrical shaped member 409 which allows theplunger to move up and down in opening 415 without binding. Plunger 403has a skirt 429 which has, at its end, an external, outwardly projectingridge 433. Shoulder 417 in cylindrical shaped member 409 and ridge 433on the plunger 403 engage each other to keep plunger 403 captive withinmember 409.

Actuator 405, which can be composed of cold rolled steel or a plastichaving suitable characteristics supports an elongated shaft 421 having agenerous radius at one end and first 423 and second 425 collars at theother end. Collar 423 is smaller in diameter than collar 425 and isadapted to be frictionally connected to the smaller diameter end ofconical spring 407. The end of the second collar 425 is located withinopening 428 of plunger 403 and contacts internal projection 427.

Coil spring 407 has a conical shape, the apex of which is wrapped aroundand frictionally engages collar 423 and the base of spring 407 issufficiently large in diameter to extend beyond the rectangularclearance opening 402 to avoid interfering with shaft 421 as it pivotsback and forth in the rectangular clearance opening 402. Opening 402 hasa long dimension along the length of the switch and a small dimensionalong the width of the switch. The small dimension of opening 402 isslightly larger than the diameter of shaft 421 to permit the shaft 421to move in opening 402 without binding and the long dimension of opening402 allows shaft 421 to engage and operate cam 366 without binding.

A small projection 406 which extends upward from the bottom 401 of frameassembly 400 and of the same material as the bottom member can be usedto engage the lower end of a helper helical spring 408 which is providedto urge the rocker paddle 112 to its out position. In normal use, thespring 407 will provide sufficient force to urge the paddle 112 awayfrom frame assembly 400. However, in those instances where additionalforce may be desired, helper spring 408 can be present. The outsidediameter of the projection 406 is slightly less than the inside diameterof helical helper spring 408 and fits within an end of the helicalhelper spring. The upper end of helical helper spring 408 is locatedwithin and held captive in a pocket 410 (see FIG. 17) located insubplate 412. Subplate 412 is secured to the underside of the rockerpaddle 112 by adhesive, by plastic projections which extend from theunderside of the rocker paddle and, after passing through openings inthe subplate are staked over, or the like.

Referring to FIG. 17, there is shown a perspective exploded view of thebottom of base assembly 300, frame assembly 400 and rocker assembly 398of a single pole switch. Referring to the frame assembly 400 which canbe a unitary member formed of a suitable plastic, two projections 414project out from the bottom surface and are positioned to contact thetop surface of the axel support shaft formed by aligned cylindricalprojections 368 of the cam 366. Projections 414 prevent the cylindricalprojections 368 from moving out of their bearing surfaces in the sidewalls of the slider receiving channel. Also projecting downward from thebottom surface of the frame assembly 400 is a slider hold downprojection 416 which slidably contacts projection 326 on the slider 320.Projection 416, by contacting projection 326 on slider 330, preventsslider 320 from being pushed up and out of channel 304 by the upwardforce of cam profile leaf spring 352 pushing up on triangular shaped camfollower 324.

The subplate 412 is attached to the underside of paddle 112 and is aunitary member of a plastic material having two hook shaped members 418formed thereon which project down from the bottom surface. The hookshaped members 418 are positioned to engage hooks 396 on the frameassembly 400. Hooks 418, when engaged by hooks 396, allow the rockerassembly to move toward and away from the frame assembly 400 and, at thesame time, prevent the subplate and attached rocker paddle from beingseparated from the frame assembly 400. A downward extending ring 410 onthe subplate 412 is aligned with projection 406 on the frame assembly toprovide an anchor for the top end of helper spring 408 when a helperspring is used. The inside diameter of ring 410 is slightly larger thanthe outside diameter of the helper spring to permit the end of thehelper spring to be placed within ring 410. Two arms 422 which projectbeyond the rear end of the subplate 412 each supports a circular stud420, one on the outside end of each arm, are axially aligned with eachother to form a common axel. The studs snap into openings 424 in theframe assembly 400 to form a hinge about which the subplate and therocker paddle 112 to pivot relative to the frame and base assemblies.The subplate 412 is secured to the bottom surface of the rocker paddle112 to form a unitary assembly with an adhesive, by heat staking or thelike.

The switch here disclosed can have an on-off indicating means such as alight to indicate when the switch is in its conducting state and when inits non-conducting state. The on-off indicating light can be of a coloror white. In practice, a blue light was found to be preferred. Referringto FIGS. 21A and 21B, there is shown the top and bottom of a PrintedCircuit Board (PCB) which fits within the frame assembly 400. Located onthe top surface of the board 430 is a resistor 432, a diode 434 and anLED 436 connected together and to spring terminals 390. Referring toFIG. 14, frame assembly 400 fits on top of base assembly 300 andprovides support for the PCB and has openings for the spring contacts390 to project through the frame assembly and make contact with plate313 of the stationary terminal assembly and plate 380 of the brushterminal assembly 346. LED 436 indicates the conductive state of theswitch by being “on” or “off”. In operation, lamp 394 will be “on” whenthe contacts of the switch are open, and the lamp will be “off” when thecontacts of the switch are closed.

Referring now to FIG. 23, there is shown a light pipe 440 which isconnected to the underside of the paddle (see FIG. 22) to opticallyconnect the LED to a window 442 in the lower end of the paddle. The endof the light pipe adjacent to the LED has a spherical face for receivinglight from the LED, and the other end of the light pipe has a diffusertexture exit surface which is the window in the edge of the paddle.

Referring to FIG. 24, to assemble the switch, the helper spring 338 isinserted into end chamber 340, leaf spring 352 is place into springchamber 354 and slider 320 is placed into channel 304. The end 342 ofthe slider faces the helper spring 338 and the triangular shaped camfollower 324 which projects from the bottom of the slider slidablyengages the top surface of leaf spring 352. Projecting cylindrical studs368 of cam 366 are placed within bearing surface openings 378 in sidewalls 319, 321 of channel 304 with cam follower 370 being positionedwithin opening 322 of slider 320. Stationary terminal assembly 312 ispositioned in the opening 309, and brush terminal assembly 346 ispositioned within opening 384. As the brush terminal assembly 346 isbeing placed in position, the spring contact arm 344 is moved backwardagainst the force of the spring arm and is positioned within slot 329located between the holding down projection 326 and the spring contactarm control member 327 of slider 320. At this time all the variouscomponents have been placed within the switch base 300 and theassemblage resembles that shown in FIG. 24.

Referring now to the frame assembly 400 and the cam driver 431, plunger403 is positioned within the cylindrical shaped member 409 by insertingthe plunger 403 through the bottom opening of the cylindrical shapedmember 409 until the outwardly extending ridge 421 at the end of theskirt of the plunger engages inwardly projecting ridge 417 of theplunger. Thereafter, actuator 405 is inserted through the bottom openingof the cylindrical shaped member 409 and into the plunger until the topsurface of collar 425 contacts internal projection 427 which extendsdownward from the inside surface of the top of the plunger 403. Conicalshaped coil spring 407 is now inserted through the bottom opening of thecylindrical shaped member 409 and placed around the actuator 405 withthe apex of the coil spring being positioned around the collar 423. Atthis time the assembled cam driver 431 is positioned onto the bottommember 401 of the frame 400 with the actuator being positioned to freelymove through elongated opening 402 and the clearance openings in theframe being aligned with the threaded openings in the ears of thecylindrical shaped member.

The frame assemblage 400, which includes the LED, resistor, diode andcontacts 390, is now placed over the switch base, a ground/mountingstrap is placed along the bottom and ends of base assembly 300, andscrews, drive pins, rivets or the like 124 are used to lock theground/mounting strap, switch base assemblage and frame assemblagetogether. In the embodiment shown, the conical shaped coil spring 407exerts an upward force on the actuator and the plunger to maintain theplunger in its extended most outward position. The subplate has a cutout433 through which the plunger 403 passes to contact the underside of therocker paddle 112. Thus, top surface of the plunger contacts the bottomsurface of the rocker and it is the upward force of the spring 407 thatbiases the rocker to its outward position and that a user must overcomewhen the switch is being operated. In some instances, it may bedesirable to have a switch which requires a greater force to operate. Ifa greater force is desired, it can be obtained with a helical spring 429where the lower end is placed over projection 406 on the frame and thetop is placed within the spring pocket 410 of the subplate. Theprojections 420 on the legs 422 are snapped into the openings 424 in theframe assembly 400 to form the hinge which allows the rocker assembly398 and the frame assembly 400 to pivot relative to each other.Thereafter the rocker assembly 398 which includes the subplate, ispressed down toward the frame assembly until hooks 418 engage hooks 396.At this time the bottom or underside of the rocker assembly contacts thetop surface of the plunger 403 and the application of finger pressure onthe rocker assembly will move it toward the frame assembly against theforce of spring 407 to drive the elongated shaft 421 of the actuator 405down through the opening 402 to engage the cam eccentric surface 372.

FIG. 24 is a sectional view of a single pole switch where the contactsof the switch are closed and the switch is in its conducting state. Thenext time the face of the rocker paddle is pressed, plunger 421, actingagainst the force of spring 407, is urged to move down to contact theramp 430 of cam 366 and slide toward the right and enters pocket 372.Continued pressing on the rocker paddle causes the actuator 405 tocontinue to move down and rotate cam 366 clockwise about cylindricalprojections 368. This causes cam follower 370 to rotate in a clockwisedirection and move slider 320 to the left. As slider 320 moves towardthe left, the triangular shaped cam follower 324 moves out of depression360 of the spring and across the right support section 359 toward thecentrally located apex 358 of the cam shaped leaf spring 352. As theslider continues to move to the left, triangular shaped cam 324 deflectsleaf spring 352 downward because projection 326 on slider 320, incooperation with holding projection 416, prevents the slider 320 frommoving upward. As the triangular shaped cam 324 moves over the top ofthe apex 358 of the spring and toward the left support section 359 ofthe apex, the leaf spring starts to spring back to its originalunstressed position by moving up. This upward movement of the leafspring acts on the shaped cam follower 324 and helps drive andaccelerate the cam follower 324 and the slider 320 to the left until thecam follower 324 comes to rest in depression 362. At this time thecontacts of the switch are separated from each other. Thus, the camshaped leaf spring 352, in combination with the cam follower 324 helpsto move the slider to either the left or right depressions 362, 360 torapidly open and close the contacts. The next time that the rocker isdepressed, the actuator 405 will enter pocket 374 of the cam to cause itto rotate in a counterclockwise direction which will cause the slider todepress the leaf spring as it moves to the right. As the cam follower324 continues to move to the right and as it passes apex 358, thedepressed leaf spring starts to spring up to return to its originalposition. This upward movement of the leaf spring causes the camfollower 324 to move toward the right until it reaches depression 360 atwhich time the switch contacts are closed. Continued pressing andreleasing the rocker paddle of the switch alternately opens and closesthe contacts of the switch. The state of conduction of the switch can bedisplayed to a user by light from an LED, a neon lamp or a pilot lightconnected across the stationary and brush terminal assemblies. When thecontacts of the switch are closed, there is no potential differenceacross the lamp-resistor combination and the lamp will remain dark. Whenthe contacts of the switch are open, there will be a potentialdifference across the lamp-resistor combination and the lamp will belit.

Referring to FIGS. 25A, 25B and 25C, there is shown sectional views ofpaddle 112 of the switch of FIG. 14. FIG. 25A is a section along theline A-A of FIG. 14; FIG. 25B is a section along the line B-B of FIG.14; and, FIG. 25C is a section along the line C-C of FIG. 14. The widthof the paddle is 1.79 inches and the length of the paddle is 2.77inches. The face of the paddle has a vertical axis along its length anda horizontal axis along its width where the face of the paddle along itsvertical axis has a surface of positive first differential comprised ofa combination of splines drawn between points of varying distances froma datum plane and zero second differential when the rate of heightincrease of the individual splines is constant. The horizontal axis hasa surface of a positive first differential and negative seconddifferential comprised of a combination of splines drawn between pointsof varying distance from a datum plane. Referring to FIG. 25A, thesurface along line A-A lies between two profile boundaries substantially0.139 inches apart, perpendicular to datum plane A, equally disposedabout the true profile and positioned with respect to a datum plane. Thebasic dimensions and the profile tolerance establish a tolerance zone tocontrol the shape and size of the surface. The surface is about 2.77inches in length. Within that length, a surface is defined by thedimensions of about twenty equidistant points which are about 0.139inches apart. Each dimension indicates that point's distance to a datumplane A, the back, flat surface of the paddle. Moving from left to rightin FIG. 25A, the dimensions increase from about 0.277 to about 0.328inches at the center, and then decreases to about 0.278 inches at theright end. This progression defines a surface of increasing and thendecreasing height where the points are connected by individual splines.The points are not connected by a single arc and the rate at which thesurface height increases in not constant. The rate of height increase ofthe individual splines decreases from left to right to the center, andthen increases from the center to the right end. Thus, the seconddifferential of the surface is negative from each end toward the center.That is that the difference between some of the points distancedimension from an end toward the center decreases. Thus, from an end tothe center, the surface has a shape of positive first differential andnegative second differential, comprised of a combination of splicesdrawn between points of varying distance from a datum plane. Thisdescription substantially describes the paddle's face along the linesA-A, B-B and C-C of FIG. 14.

The section along line B-B of FIG. 14 which runs along the horizontalcenter line of the paddle is shown in FIG. 25B and defines a surfacehaving positive first differential and substantially negative seconddifferential from an end to the center line. The second differential issubstantially negative because not all successive points have a constantincrease.

The section along line C-C of FIG. 14 which runs along the diagonal ofthe paddle is shown in FIG. 25C and defines a surface having a positivefirst differential and substantially negative second differential froman end to the center line. The second differential is substantiallynegative because not all successive points have a constant increase.

FIGS. 25A-25C discloses, in detail, the dimensions of the paddle and,therefore, in the interest of brevity, the dimensions shown in the FIGS.25A-25C are not here repeated.

Referring to FIG. 26, there is shown an exploded view of the switch withanother cam driver; and, FIG. 27 is a sectional view along line 24-24 ofFIG. 3 where the cam driver is that of FIG. 26. In this embodiment, thearticulated cam driver 431 shown in FIG. 19 is replaced with a flexiblecam driver with blunt end 600. Flexible cam driver with blunt end 600 iscomposed of a flat ribbon of flexible material such as spring steel bentback upon itself at its center with a generous radius to form the bluntend 602 having a diameter which fits within the pockets 372, 374 of cam366. The ends of the flexible cam driver are bent at 90 degrees and eachend has an opening for receiving a holding member for attaching theflexible cam driver to the subplate 412. In this embodiment, subplate412 does not have a cutout 433, but is continuous to provide support forand allow the flexible cam driver 600 to be attached to the subplate.Cam driver 600 can be attached to the subplate with rivets, plasticprojections which protrude from the subplate and pass through theopenings in the ends of the cam driver and are deformed with heat tosecure the cam driver to the subplate, or by any other method. Exceptfor the substitution of the flexible cam driver with blunt end 600 forthe articulated cam driver 431 disclosed in FIG. 19, the constructionand operation of the switch of the embodiment disclosed in FIGS. 26 and27 is the same in all aspects as that of the switch disclosed in FIGS.14-25C.

Referring to FIG. 28, there is shown an exploded view of the switch withstill another cam driver, and FIG. 29, is a sectional view along line24-24 of FIG. 3 where the cam driver is that of FIG. 28. In thisembodiment, the articulated cam driver 431 shown in FIG. 19 is replacedwith a semiflexible cam driver having a sharp end 700 such as a closelywound coil spring 700 having a conical shaped tip 702. In thisembodiment, subplate 412 does not have a cutout 433, but is continuousto provide support for and to allow the semiflexible cam driver 700 tobe attached to the subplate. The subplate has a small projection whichextends down from the bottom of the subplate and has a diameter the fitssnugly within the top end of the closely wound spring. The closelyspring 700 is attached to the subplate by being placed over theprojection on the subplate. The lower end of the closely wound spring700 supports a conical shaped tip 702 having a cylindrical back endhaving a diameter which is substantially equal to that of the insidediameter of the spring 700 and which is inserted into and held securelyby the closely wound spring. The very tip of the conical shaped tip 702has a small diameter which allows it to fit into pockets 372 and 374 ofcam 366. Except for the substitution of the semiflexible cam driver withsharp end for the articulated cam driver 431 disclosed in FIG. 19, theconstruction and operation of the switch of the embodiment disclosed inFIGS. 28 and 29 is the same in all aspects as that of the switchdisclosed in FIGS. 14-25C.

Referring to FIGS. 30-35, for a single wiring device, the width of theface of the wiring device is approximately 55% of the width of the wallplate along the horizontal axis and approximately 56% of the length ofthe wall plate along the vertical axis. When the wiring device is areceptacle, the surface along the width of the receptacle face is flatin one plane and is complex along the length of the face of thereceptacle with a constant radius that is greater than 10 inches andless than 40 inches, a preferred radius being substantially 30.724inches. The shape of the receptacle face is different from that of theswitch to allow for the proper seating of an inserted plug. When thewiring device is a switch, its face has a vertical axis along its lengthand a horizontal axis along its width where the face of the paddle alongits vertical axis has a surface of positive first differential comprisedof a combination of splines drawn between points of varying distancesfrom a datum plane and zero second differential when the rate of heightincrease of the individual splines is constant. The horizontal axis hasa surface of a positive first differential and negative seconddifferential comprised of a combination of splines drawn between pointsof varying distance from a datum plane. Referring to FIG. 30, there isshown a front perspective view of a wall plate for a single wiringdevice. The wall plate is substantially 4.92 inches in length by 3.28inches in width and has a single opening 100 with no dividing membersfor receiving a wiring device, either a switch which has no frame or areceptacle each of which is slightly less than 2.82 inches in length by1.83 inches in width to fit within the opening 100. The width of thewall plate varies depending upon how many wiring devices are gangedtogether and located in side-by-side relationship. The front surface ofthe wall plate here disclosed has a complex or compound shape such thatthe surface at the opening for the wiring device is further from thewall than it is at the outer edge of the wall plate. Referring to FIG.31B, there is shown a view along the line 31B-31B of FIG. 30. FIGS.31A-31C are sectional views along the lines 31A-31A to 31C-31C of thewall plate of FIG. 30 along the horizontal centerline, between point K,the outer right edge, and point L, the inner edge of the opening for thewiring device. As shown in FIG. 31B, the surface lies between twoprofile boundaries substantially 0.002 inches apart, perpendicular todatum plane A, equally disposed about the true profile and positionedwith respect to a datum plane. The basic dimensions and the profiletolerance establish a tolerance zone to control the shape and size ofthe surface. The surface is about 0.73 inches in width. Within thatwidth, a shape is defined by the dimensions of about ten equidistantpoints which are about 0.073 inches apart. Each dimension indicates thatpoint's distance to datum plane A, the back (flat) surface of the wallplate, which begins at point K. Moving from left to right, thedimensions increase from about 0.243 to about 0.302 inches. Thisprogression defines a shape of increasing height, positive firstdifferential, when the points are connected by individual splines. Thepoints are not connected by a single arc and the rate at which the shapeheight increases is not constant. The rate of height increase of theindividual splines decreases from left to right, and the seconddifferential of the shape is negative. That is, the difference betweenthe first point's distance dimension and the second is larger than thedifference between the second and the third, etc. Thus, the surface hasa shape of positive first differential and negative second differential,comprised of a combination of splines drawn between points of varyingdistance from a datum plane. FIG. 31A is a sectional view along the line31A-31A of FIG. 30; FIG. 31B is a sectional view along the line 31B-31Bof FIG. 30; and FIG. 31C is a sectional view along the line 31C-31C ofFIG. 30. FIGS. 31A-C clearly shows the wall plate's shape for sectionsalong lines 31A-31A, 31B-31B and 31C-31C of FIG. 30.

The section along line 31C-31C (see FIG. 31C), which runs along thevertical centerline of the wall plate defines a surface having apositive first differential and zero second differential, comprised of acombination of splines drawn between points of varying distance from adatum plane. This surface has zero second differential because the rateof height increase of the individual splines is constant; the differencebetween any two sequential point dimensions is substantially 0.0037inches.

The wall plate 138 for a single wiring device shown in FIG. 30 includes,along the inside top edge, and the inside bottom edge, a plurality ofteeth for engagement with the ends of latching pawls 140 of themulti-function clips 130, 151. See FIG. 32 which is a sectional view ofthe bottom edge of the wall plate along the line 32A-32A of FIG. 30; andFIG. 33 which is a sectional view of the top edge of the wall platealong the line 33A-33A of FIG. 30. The top outside edge (see FIG. 33),has a recessed area such as a channel having raised identifyingnomenclature structure such as letters of the alphabet, numbers and/or asymbol which can, for example, identify the manufacturer of the device.Referring to FIG. 33, there is also shown a sectional view along theline E-E of FIG. 30 of the top rail of the wall plate 138. FIGS. 34, 34Ashow views of a portion of the top edge of the wall plate of FIG. 30showing the channel and identifying nomenclature structure. In FIGS. 34and 34A, a channel 217 (see FIG. 33) is formed in the top outside edgeof the wall plate. The channel is about three-quarters of an inch inlength and has a width which is less than the width of the edge of therail. As shown in FIGS. 33, 34, 34A, channel 217 is a walled rectangulardepression defined by four walls which define the channel. Locatedwithin the channel or depression is raised identifying structure such asthe name of the manufacturer, i.e., “LEVITON”. The height of the raisedidentifying structure can be 0.010 of an inch where the top surface ofthe raised identifying structure is substantially flush with the surfaceof the edge of the wall plate.

When the wiring device of the present invention is a switch, the surfaceof the paddle of the switch is a continuation of contours of the wallplate, so that their surfaces complement each other. When the wiringdevice is a receptacle, the contour along the width of the receptacleface is flat in one plane and is complex along the length of the face ofthe receptacle with a constant radius. The shape of the receptacle faceis different from that of the switch to allow for the proper seating ofan inserted plug. The wall plate has no exposed mounting screws or othervisible metal hardware. When the wall plate is placed around the wiringdevice, the only visible parts are the wall plate 16 and the switch orreceptacle. No fastening means such as screws for holding the wall platein place are visible.

To attach the wall plate 138 to the wiring device, the edges of pawls140 of the bottom and top clips 130, 151 engage tooth shaped racks 80located on the inner surfaces of the top and bottom end walls 70 of wallplate 138. There are two racks on each end wall 70 of the wall plate138. Each rack 80 contains a number of tooth shaped teeth 82 each havingan inclined front face 84 and an inclined back face 86. Referring toFIG. 35, which is a fragmentary, enlarged perspective of the latchingpawl of the multi-function clip engaging the tooth rack of the wallplate as the end of latching pawl 140 engages the inclined front face 84of a tooth, the pawl deflects and moves past the tip of the first tooth82. Once pawl 140 is past the tip of tooth 82, it can return to itsinitial position and take a position between the inclined back face 86of first tooth 82 and the inclined front face 84 of a second tooth 82.This operation can be repeated as many times as is needed to positionthe top and bottom ends of wall plate 138 as close to the wall aspossible. As racks 80 and pawls 140 are independently operated, it ispossible to position the wall plate 138 to closely follow the wallcontour, even when the wall is not flat. This ability to follow the wallcontour is even more appreciated when the wall plate 138 is large, suchas a wall plate positioned around multiple wiring devices.

Referring to FIG. 36, there is shown a fragmentary, enlarged sectionalside view of the wall plate and tab of the alignment plate to indicatehow the two components can be separated following latching. Once theends of latching pawl 140 is positioned in a valley between two teeth,it becomes difficult to dislodge the wall plate 138 from the pawl 140.To help in the removal of the wall plate a slot 74 is formed in thebottom end 70 of wall plate 138 to provide access to tab 120. A small,flat tool blade such as a screw driver blade 76, or the like, can bemoved through slot 74 in end 70 to contact both the outer surface of tab120 and the back wall of slot 74. By moving the blade 76 using the backwall of slot 74 as a fulcrum, the force applied to tab 120 will separatewall plate 138 from the wiring device. As tool 76 can apply a great dealof force to tab 120, it is possible to separate the pawl 140 fromengagement with the teeth and thus the wiring device from the wallplate.

Referring to FIG. 37, there is shown an exploded view of alignment plateand a wall plate for two wiring devices. There is no partition ordividing member located in either the wall plate opening or thealignment plate opening to separate the two wiring devices. The twowiring devices can be placed in a double ganged box 160 made up, forexample, of two single boxes joined by fasteners 162 extending throughthe threaded apertures 164 of two joining ears 166. Alignment plate 114has a single opening 116, four clearance openings 117 and four alignmentpins 170 for receiving two wiring devices such as two switches, areceptacle and a switch, or two receptacles.

Wall plate 138 can have four racks 80 on the interior of the top andbottom end walls for receiving four pawls where the two center racksreceive one pawl from each wiring device. Also, there are two tabs 120,which are accessible via slots 74 in end wall 70 of cover plate 138.Because of the independent operation of the pawls 140 with theirrespective racks 80, the wall plate 138 can compensate somewhat for lackof flatness of the wall in which the wiring devices are installed.

Referring to FIG. 38, there is shown an exploded view of alignment plate114 having a single opening 116 and a wall plate 138 for three wiringdevices mounted in three boxes (not illustrated) ganged together. Wallplate 138 has a single opening 100 with no dividing or separatingmembers for receiving three wiring devices positioned side by side andhas four sets of racks 80 where the two end racks each receive a singlepawl and the two center racks receive two pawls. Alignment plate 114 hasa single opening 116 with no dividing or separating members, three setsof clearance openings 117 and three sets of alignment pins 170 forreceiving three wiring devices.

Referring to FIG. 39, there is shown an exploded view of alignment plate114 having a single opening 116 with no dividing or separating membersand wall plate 138 for four wiring devices mounted in four boxes (notillustrated) ganged together. Wall plate 138 has a single opening 100with no dividing or separating members for receiving four wiring devicespositioned side by side and the alignment plate 114 has a single opening116 with no dividing or separating members for receiving four wiringdevices positioned side by side.

FIG. 40 is an exploded view of alignment plate 114 having a singleopening 116 with no dividing or separating members and wall plate 138having a single opening 100 for five wiring devices mounted in fiveboxes (not illustrated) ganged together. The single opening 100 in wallplate 138 has no dividing or separating members and the alignment plate114 has a single opening 116 with no dividing or separating members forreceiving five wiring devices positioned side by side.

FIG. 41 is an exploded view of alignment plate 114 having a singleopening 116 with no dividing or separating members and wall plate 138having a single opening 100 for six wiring devices mounted in six boxes(not shown) ganged together. The single opening 100 in wall plate 138has no dividing or separating members and the alignment plate 114 has asingle opening 116 with no dividing or separating members for receivingsix wiring devices positioned side by side.

Each wall plate shown in the FIGS, can be made of conductive material orof non-conductive material. Where the wall plate is made ofnon-conductive material such as plastic, a conductive coating can besprayed, plated, etc. to the front, back or both the front and backsurfaces of the wall plate to provide a conductive path from the wallplate to ground through the alignment plate. In those instances wherethe wall plate is coupled to the wiring device by means other than thealignment plate here shown, such as, for example, with screws etc., thenthe conductive path from the wall plate to ground is via the means thatattaches the wall plate to the wiring device and/or box.

The present invention contemplates a system wherein multiple electricalwiring devices in numbers not expressly set forth hereinabove may beutilized, without departing from the spirit or lawful scope of theinvention.

While there have been shown and described and pointed out thefundamental novel features of the invention as applied to the preferredembodiments, it will be understood that various omissions andsubstitutions and changes of the form and details of the devicesillustrated and in their operation may be made by those skilled in theart without departing from the spirit of the invention.

1. A wall plate for covering a wall box mountable wiring devicecomprising: a frame having a vertical axis along its length and ahorizontal axis along its width and a single opening for a plurality ofwiring devices.
 2. The wall plate of claim 1 wherein the single openingfor a plurality of wiring devices is centrally located.
 3. The wallplate of claim 2 wherein the single centrally located opening is sizedfor less than three wiring devices.
 4. The wall plate of claim 1 whereinthe plurality of wiring devices are positioned in side by siderelationship.
 5. The wall plate of claim 1 wherein the wiring devicesare positioned in side be side relationship without a separating memberon the cover for separating the devices.
 6. The wall plate of claim 5wherein the thickness of the frame changes at a rate that is notconstant.
 7. The wall plate of claim 6 wherein a section along thevertical axis of the wall plate has a surface of positive firstdifferential comprised of a combination of splines drawn between pointsof varying distance from a datum plane.
 8. The wall plate of claim 7wherein the section along the vertical axis of the wall plate has asurface with a contour of zero second differential comprised of splinesdrawn between points of varying distance from a datum plane when therate of height increase of the individual splines is constant.
 9. Thewall plate of claim 6 wherein a section along the horizontal axis fromthe outer edge of the wall plate to the edge of the opening has asurface of a positive first differential and negative seconddifferential, comprised of a combination of splines drawn between pointsof varying distance from the datum plane.
 10. The wall plate of claim 6wherein a section along the vertical axis of the wall plate has asurface of positive first differential, comprised of splines drawnbetween points of varying distance from a datum plane, and a sectionalong the horizontal axis from the outer edge of the wall plate to theedge of the opening has a surface of a positive first differential,comprised of a combination of splines drawn between points of varyingdistance from the datum plane.
 11. The wall plate of claim 10 whereinthe section along the horizontal axis from the outer edge of the coverplate to the edge of the opening has a surface of negative seconddifferential, comprised of a combination of splines drawn between pointsof varying distance from the datum plane.
 12. The wall plate of claim 11wherein the section along the vertical axis of the wall plate has asurface with a contour of zero second differential comprised of splinesdrawn between points of varying distance from a datum plane when therate of height increase of the individual splines is constant.